<?php

/**
 * @file
 * Contains the feed display plugin.
 */

/**
 * The plugin that handles a feed, such as RSS or atom.
 *
 * For the most part, feeds are page displays but with some subtle differences.
 *
 * @ingroup views_display_plugins
 */
class views_plugin_display_feed extends views_plugin_display_page {

    function uses_breadcrumb() {
        return FALSE;
    }

    function get_style_type() {
        return 'feed';
    }

    /**
     * Feeds do not go through the normal page theming mechanism. Instead, they
     * go through their own little theme function and then return NULL so that
     * Drupal believes that the page has already rendered itself...which it has.
     */
    function execute() {
        $output = $this->view->render();
        if (empty($output)) {
            return drupal_not_found();
        }
        print $output;
    }

    function preview() {
        if (!empty($this->view->live_preview)) {
            return '<pre>' . check_plain($this->view->render()) . '</pre>';
        }
        return $this->view->render();
    }

    /**
     * Instead of going through the standard views_view.tpl.php, delegate this
     * to the style handler.
     */
    function render() {
        return $this->view->style_plugin->render($this->view->result);
    }

    function defaultable_sections($section = NULL) {
        if (in_array($section, array('style_options', 'style_plugin', 'row_options', 'row_plugin',))) {
            return FALSE;
        }

        $sections = parent::defaultable_sections($section);

        // Tell views our sitename_title option belongs in the title section.
        if ($section == 'title') {
            $sections[] = 'sitename_title';
        } elseif (!$section) {
            $sections['title'][] = 'sitename_title';
        }
        return $sections;
    }

    function option_definition() {
        $options = parent::option_definition();

        $options['displays'] = array('default' => array());

        // Overrides for standard stuff:
        $options['style_plugin']['default'] = 'rss';
        $options['style_options']['default'] = array('mission_description' => FALSE, 'description' => '');
        $options['sitename_title']['default'] = FALSE;
        $options['row_plugin']['default'] = '';
        $options['defaults']['default']['style_plugin'] = FALSE;
        $options['defaults']['default']['style_options'] = FALSE;
        $options['defaults']['default']['row_plugin'] = FALSE;
        $options['defaults']['default']['row_options'] = FALSE;

        return $options;
    }

    function options_summary(&$categories, &$options) {
        // It is very important to call the parent function here:
        parent::options_summary($categories, $options);

        // Since we're childing off the 'page' type, we'll still *call* our
        // category 'page' but let's override it so it says feed settings.
        $categories['page'] = array(
            'title' => t('Feed settings'),
        );

        if ($this->get_option('sitename_title')) {
            $options['title']['value'] = t('Using the site name');
        }

        // I don't think we want to give feeds menus directly.
        unset($options['menu']);

        $displays = array_filter($this->get_option('displays'));
        if (count($displays) > 1) {
            $attach_to = t('Multiple displays');
        } else if (count($displays) == 1) {
            $display = array_shift($displays);
            if (!empty($this->view->display[$display])) {
                $attach_to = check_plain($this->view->display[$display]->display_title);
            }
        }

        if (!isset($attach_to)) {
            $attach_to = t('None');
        }

        $options['displays'] = array(
            'category' => 'page',
            'title' => t('Attach to'),
            'value' => $attach_to,
        );
    }

    /**
     * Provide the default form for setting options.
     */
    function options_form(&$form, &$form_state) {
        // It is very important to call the parent function here.
        parent::options_form($form, $form_state);

        switch ($form_state['section']) {
            case 'title':
                $title = $form['title'];
                // A little juggling to move the 'title' field beyond our checkbox.
                unset($form['title']);
                $form['sitename_title'] = array(
                    '#type' => 'checkbox',
                    '#title' => t('Use the site name for the title'),
                    '#default_value' => $this->get_option('sitename_title'),
                );
                $form['title'] = $title;
                $form['title']['#process'] = array('views_process_dependency');
                $form['title']['#dependency'] = array('edit-sitename-title' => array(FALSE));
                break;
            case 'displays':
                $form['#title'] .= t('Attach to');
                $displays = array();
                foreach ($this->view->display as $display_id => $display) {
                    if (!empty($display->handler) && $display->handler->accept_attachments()) {
                        $displays[$display_id] = $display->display_title;
                    }
                }
                $form['displays'] = array(
                    '#type' => 'checkboxes',
                    '#description' => t('The feed icon will be available only to the selected displays.'),
                    '#options' => $displays,
                    '#default_value' => $this->get_option('displays'),
                );
                break;
            case 'path':
                $form['path']['#description'] = t('This view will be displayed by visiting this path on your site. It is recommended that the path be something like "path/%/%/feed" or "path/%/%/rss.xml", putting one % in the path for each argument you have defined in the view.');
        }
    }

    /**
     * Perform any necessary changes to the form values prior to storage.
     * There is no need for this function to actually store the data.
     */
    function options_submit(&$form, &$form_state) {
        // It is very important to call the parent function here:
        parent::options_submit($form, $form_state);
        switch ($form_state['section']) {
            case 'title':
                $this->set_option('sitename_title', $form_state['values']['sitename_title']);
                break;
            case 'displays':
                $this->set_option($form_state['section'], $form_state['values'][$form_state['section']]);
                break;
        }
    }

    /**
     * Attach to another view.
     */
    function attach_to($display_id) {
        $displays = $this->get_option('displays');
        if (empty($displays[$display_id])) {
            return;
        }

        // Defer to the feed style; it may put in meta information, and/or
        // attach a feed icon.
        $plugin = $this->get_plugin();
        if ($plugin) {
            $clone = $this->view->clone_view();
            $clone->set_display($this->display->id);
            $clone->build_title();
            $plugin->attach_to($display_id, $this->get_path(), $clone->get_title());

            // Clean up
            $clone->destroy();
            unset($clone);
        }
    }

    function uses_link_display() {
        return TRUE;
    }

}
